All that I know is nothing - I'm not even sure of that.

There is no learning without remembering.

To harm another is to harm oneself

The young people of today think of nothing but themselves. They have no reverence for parents or old age. They are impatient of all restraint. They talk as if they alone knew everything and what passes for wisdom with us is foolishness with them. As for girls, they are forward, immodest and unwomanly in speech, behaviour and dress.

I have not sought during my life to amass wealth and to adorn my body, but I have sought to adorn my soul with the jewels of wisdom, patience, and above all with a love of liberty.

Not I, but the city teaches.

By all implies marry if you get a great wife/husband, you are going to be pleased. If you get a bad a single, you are going to become a philosopher.